Conventionally, there has been known a transmission apparatus (for example, a wireless communication apparatus) that determines a PHY rate for transmitting packets using a reception power value of a packet. When receiving a packet from a wireless network via an antenna, the transmission apparatus detects a reception power value of the received packet, and determines a PHY rate corresponding to the detected reception power value based on a correspondence table that has been stored therein in advance and shows correspondence between reception power values and PHY rates. Then, the transmission apparatus performs data transmission/reception at the determined PHY rate (for example, see Patent Document 1). Accordingly, it is possible to optimize a communication rate for transmitting data, and improve the efficiency in data transmission/reception.    [Patent Document 1] Japanese Laid-Open Patent Application Publication No. 2002-186027